The Biomolecular Mass Spectrometry Facility at the University of California San Diego wishes to acquire a 2D nano-flow mass spectrometer system. The configuration we propose consists of an LC Packings U-3000 Nano-LC with Switches and Ultimate-3000 Dual pumps for 2D chromatography interfaced to a Finnigan LTQ with Sequest Sorcerer data analysis cluster. This combination has the reliability, high-throughput capabilities, and sensitivity required for the proposed studies. This instrument will be used in proteomics studies to understand how specific gene products work to impact cellular function and human health. The mass spectrometer system will be used to discover interaction complexes, to identify post-translational modifications, and to identify pathways of bioactive peptide generation. The goals of the proposed research projects include identification of proteins in complexes in a robust and comprehensive way. In particular, we will analyze protein complexes involved in Alzheimer's Disease, cancer, and bacterial pathogenesis. Also, proteomics of the biosynthetic pathways of bioactive peptides involved in pain and blood pressure control, and the proteases that generate them will be carried out. Analysis of post-translational modifications, beginning with phosphorylation of the kinase anchoring proteins, is also planned. Finally, a novel approach to identifying proteins that are in close proximity by not necessarily binding directly is proposed. Professors E. Komives, J. Dixon and S. Taylor will identify proteins in complexes. Professors V. Hook and D. T. O'Connor will analyze the biosynthesis of bioactive peptides. Professor R. Tsien will explore the possibilities of using ReAsH reagents to discover proteins in close proximity in the cell. [unreadable] [unreadable]